From: Eric Dumazet <eric.dumazet@gmail.com>
To: "Gustavo A. R. Silva" <gustavoars@kernel.org>,
"David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
David Ahern <dsahern@kernel.org>
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-hardening@vger.kernel.org
Subject: Re: [PATCH][next] net/ipv6/mcast: Use struct_size() helper
Date: Thu, 5 Aug 2021 13:00:01 +0200 [thread overview]
Message-ID: <aaa77803-fb5f-6444-ae2b-d6498ffea252@gmail.com> (raw)
In-Reply-To: <20210804214352.GA46670@embeddedor>
On 8/4/21 11:43 PM, Gustavo A. R. Silva wrote:
> Replace IP6_SFLSIZE() with struct_size() helper in order to avoid any
> potential type mistakes or integer overflows that, in the worst
> scenario, could lead to heap overflows.
>
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
> ---
> include/net/if_inet6.h | 3 ---
> net/ipv6/mcast.c | 20 +++++++++++++-------
> 2 files changed, 13 insertions(+), 10 deletions(-)
>
> diff --git a/include/net/if_inet6.h b/include/net/if_inet6.h
> index 71bb4cc4d05d..42235c178b06 100644
> --- a/include/net/if_inet6.h
> +++ b/include/net/if_inet6.h
> @@ -82,9 +82,6 @@ struct ip6_sf_socklist {
> struct in6_addr sl_addr[];
> };
>
> -#define IP6_SFLSIZE(count) (sizeof(struct ip6_sf_socklist) + \
> - (count) * sizeof(struct in6_addr))
> -
> #define IP6_SFBLOCK 10 /* allocate this many at once */
>
> struct ipv6_mc_socklist {
> diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
> index 54ec163fbafa..cd951faa2fac 100644
> --- a/net/ipv6/mcast.c
> +++ b/net/ipv6/mcast.c
> @@ -447,7 +447,8 @@ int ip6_mc_source(int add, int omode, struct sock *sk,
>
> if (psl)
> count += psl->sl_max;
> - newpsl = sock_kmalloc(sk, IP6_SFLSIZE(count), GFP_KERNEL);
> + newpsl = sock_kmalloc(sk, struct_size(newpsl, sl_addr, count),
> + GFP_KERNEL);
I find the current code is more readable.
Please only change IP6_SFLSIZE() definition maybe
prev parent reply other threads:[~2021-08-05 11:00 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-04 21:43 [PATCH][next] net/ipv6/mcast: Use struct_size() helper Gustavo A. R. Silva
2021-08-05 11:00 ` Eric Dumazet [this message]
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